302 redirect
A temporary redirect indicating the resource lives elsewhere for now; the original URL is expected to remain the canonical one.
TechnicalPermanent redirect
301 redirect
A server-side permanent redirect that tells crawlers a URL has moved for good and that ranking signals should consolidate on the destination.
In full
Google treats 301 (and 308) as a strong canonicalisation signal, though the destination must be a genuine equivalent — mass-redirecting retired pages to the homepage is treated as a soft 404. Signal consolidation is not instant; it happens as Google recrawls the old URLs. Chains should be collapsed to a single hop, and internal links should be updated to point at final destinations rather than relying on redirects.
Example
During an HTTPS migration every `http://` URL 301s to its exact `https://` equivalent, preserving path and query.
Related terms
308 redirect
A permanent redirect equivalent to 301 for indexing purposes, but which forbids changing the HTTP method when following it.
Redirect chain
A sequence of two or more redirects between the requested URL and the final destination; each hop adds latency and risks signals being lost.
Canonicalization
The process by which a search engine groups duplicate or near-duplicate URLs into a cluster and picks one representative URL to index and…
Site migration
Any change to a site's domain, URL structure, platform, template or content organisation that materially affects how search engines see it.